The game I'm mostly done writing started out with 4E's tactical combat as a foundation, but player interest led to having to incorporate all manner of hirelings (to the point that, if its sapient, you can theoretically hire it).
Many of the PC backgrounds also include options to gain more skilled (generally) and loyal followers you don't have to actually pay for (well, not in the sense of a daily wage... you DO have to pay for their food, shelter, transportation, clothing and other gear) and the aristocrat background even encourages you to take those options and use them for mundane tasks even if the PC could do it themselves... because what's the point of being a noble if you can't have people do things for you.
The result is that just about everyone has some companions unless they specifically don't want them (the vigilante in our urban/crime-focused game for example doesn't want the entanglements of companions, but the brothel madame has a bouncer, some cut throats and three ladies working for her).
The "free" followers that can be gained by the follower-heavy backgrounds top off at one elite warrior type (a bodyguard, enforcer or medic), three warriors (a lance of men-at-arms, a tribal warband or a band of thugs) and three non-combat followers (apprentices, acolytes, attendants, lackeys or a troupe of entertainers).
The default for a knight or minor noble with the companion options would have a squire (bodyguard or enforcer), lance of archers (men-at-arms), a valet, a page and a porter to handle baggage and beasts of burden (the squire would handle their lord's personal mount) as their basic retinue. They can then hire on as much additional muscle as they can afford.
The only balance for travelling with additional forces is that they cost money and that means they'll cut into the profits of your adventuring efforts. They also make fights less challenging and the default leveling method is that you level up when the GM decides you've faced enough challenging situations to have actually learned something from it... you don't improve much by throwing fifty hired soldiers at two dozen bandits.